A set top digital video recorder (DVR) is a computing device that records digital data streams for broadcast television, cable television, or satellite television. The set top DVR may be a stand-alone or portable device, integrated into a set-top box provided by a cable or satellite provider, or created using components and software in a computer. The set top DVR typically includes a large capacity hard drive for recording and storing the digital data streams for viewing at a later time. The hard drive provides the ability to watch a live digital data stream, watch a recorded digital data stream, or watch a recorded digital data stream while recording a live digital data stream.
A prior art approach for switching audio output from the broadcast audio of a live digital data stream to the sound effects audio of a recorded digital data stream, and back to the broadcast audio would stop the broadcast audio, reset the Sony Phillips Digital Interface (SPDIF) mode and the High Definition Multimedia Interface (HDMI) mode, play the local audio, reset the SPDIF mode again to compressed mode, and restart the broadcast audio. One disadvantage of this approach is that it typically results in significant delays due to stopping and starting the broadcast audio and changing the SPDIF modes. There is a need for a system and method that enables the insertion of sound effects into broadcast audio in a seamless fashion that preserves the broadcast audio frame boundaries, thereby preventing the external receiver from resetting due to buffer overflow or underflow.